Re: niced tasks on SMT system

From: Ozgur
Date: Thu Dec 28 2017 - 16:07:58 EST




28.12.2017, 23:59, "Pavel Machek" <pavel@xxxxxx>:
> Hi!
>
>> Â>> Â> Ok, so I'm compiling, and I'd like to run a flight simulator.
>> Â>> Â>
>> Â>> Â> Flightgear normally does 20fps on my system... kinda low but playable.
>> Â>> Â>
>> Â>> Â> I have reniced make -j 5 fo kernel running. Scheduler gives 100% of
>> Â>> Â> one of CPUs to Flightgear (good), but the smt sibling is used by the
>> Â>> Â> compilation, and I'm down to 9 fps. Not good.
>> Â>> Â>
>> Â>> Â> Even with single-threaded make, I have 10-13fps.
>> Â>> Â>
>> Â>> Â> Is there way to learn which CPUs are SMT siblings?
>> Â>>
>> Â>> Âcat /sys/devices/system/cpu/cpu{N}/topology/thread_siblings
>> Â>
>> Â> Thanks for a hint.
>> Â>
>> Â> Well, something is definitely wrong there:
>> Â>
>> Â> pavel@duo:/data/l/linux-n900$ cat
>> Â> /sys/devices/system/cpu/cpu0/topology/thread_siblings
>> Â> 03
>>
>> ÂOps,
>>
>> Âdo you fly on N900 via flightgear? :)
>> ÂI have two N900 and one run gentoo.
>
> No, no flightgear on N900. It was preparing kernels for my N900 that
> interfered with flying.

I would like to be involved in the team and share the job. firstly I will read the project documents.

> BTW there's lot of fun to be had with
> N900. https://wiki.postmarketos.org/wiki/Nokia_N900_(nokia-rx51) I
> even have voice calls working on Debian, help welcome :-).

I use default Maemo, the n900 is already debian, gentoo run a chroot :)

> ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂPavel

Ozgur

> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html